The economic rationale for the UK to enter into a formal agreement that would see an independent Scotland retain the pound is "not clear", a new report from the Treasury has said.
The report casts doubt over whether a deal could be reached to establish a "sterling zone" between an independent Scotland and the rest of the UK.
Chancellor George Osborne and Chief Secretary to the Treasury Danny Alexander will launch the report to an audience of business leaders in Glasgow.
Scottish Finance Secretary John Swinney has already dismissed "insulting" claims in it that Scottish banknotes could be lost under the SNP's plans to retain the pound if the country votes to leave the UK in next year's referendum.
He said: "Instead of coming north to lecture the people of Scotland, Mr Osborne should be listening, at a time when Scotland's economy and jobs market is outperforming the rest of the UK and when the Chancellor's own financial mismanagement has been exposed by the latest international ratings downgrade."
The report - one in a series of papers from the UK Government on the impact of Scottish independence - outlines four options for currency if voters north of the border decide to leave the UK.
Scotland could continue to use the pound as part of a formal agreement with the rest of the UK, creating a sterling currency union, or could instead continue to use the pound unilaterally, with no such deal in place. Alternatively it could join the euro or introduce a new Scottish currency.
The Scottish Government has already set out plans to retain the pound if the country becomes independent, creating a "sterling zone" with the rest of the UK.
Economics experts in the Fiscal Commission Working Group, set up by Scottish First Minister Alex Salmond, have concluded this is both "sensible" and an attractive choice for the rest of the UK.
But the Treasury report said a formal sterling currency union "would only be possible if both an independent Scotland and the continuing UK could reach an agreement that satisfied both countries' economic interests". It argues a formal sterling currency union would be "very different to the current arrangements and would be a profound economic change for both states".